Digital Commons Network^™

New Bounds On Augmenting Steps Of Block-Structured Integer Programs, Lin Chen, Martin Koutecký, Lei Xu, Weidong Shi

Computer Science Faculty Publications

Iterative augmentation has recently emerged as an overarching method for solving Integer Programs (IP) in variable dimension, in stark contrast with the volume and flatness techniques of IP in fixed dimension. Here we consider 4-block n-fold integer programs, which are the most general class considered so far. A 4-block n-fold IP has a constraint matrix which consists of n copies of small matrices A, B, and D, and one copy of C, in a specific block structure. Iterative augmentation methods rely on the so-called Graver basis of the constraint matrix, which constitutes a set of fundamental augmenting steps. All existing …

Mir-205: A Potential Biomedicine For Cancer Therapy, Neeraj Chauhan, Anupam Dhasmana, Meena Jaggi, Subhash C. Chauhan, Murali M. Yallapu

School of Medicine Publications

microRNAs (miRNAs) are a class of small non-coding RNAs that regulate the expression of their target mRNAs post transcriptionally. miRNAs are known to regulate not just a gene but the whole gene network (signaling pathways). Accumulating evidence(s) suggests that miRNAs can work either as oncogenes or tumor suppressors, but some miRNAs have a dual nature since they can act as both. miRNA 205 (miR-205) is one such highly conserved miRNA that can act as both, oncomiRNA and tumor suppressor. However, most reports confirm its emerging role as a tumor suppressor in many cancers. This review focuses on the downregulated expression …

Electrospun Zno/Poly(Vinylidene Fluoride-Trifluoroethylene) Scaffolds For Lung Tissue Engineering, Bahareh Azimi, Mohammad Sajad Sorayani Bafqi, Alessandra Fusco, Claudio Ricci, Giuseppe Gallone, Roohollah Bagherzadeh, Giovanna Donnarumma, M. Jasim Uddin, Masoud Latifi, Andrea Lazzeri, Serena Danti

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Due to the morbidity and lethality of pulmonary diseases, new biomaterials and scaffolds are needed to support the regeneration of lung tissues, while ideally providing protective effects against inflammation and microbial aggression. In this study, we investigated the potential of nanocomposites of poly(vinylidene fluoride-co-trifluoroethylene) [P(VDF-TrFE)] incorporating zinc oxide (ZnO), in the form of electrospun fiber meshes for lung tissue engineering. We focused on their anti-inflammatory, antimicrobial and mechano-electrical character according to different fiber mesh textures (i.e., collected at 500 rpm and 4000 rpm) and compositions: (0/100) and (20/80) w/w% ZnO/P(VDF-TrFE), plain and composite, respectively. The scaffolds were characterized in terms …

Induced Ferroelectric Phases In Srtio3 By A Nanocomposite Approach, Erik Enriquez, Qian Li, Pamela Bowlan, Ping Lu, Bruce Zhang, Leigang Li, Haiyan Wang, Antoinette J. Taylor, Dmitry Yarotski, Rohit P. Prasankumar

Physics & Astronomy Faculty Publications

Inducing new phases in thick films via vertical lattice strain is one of the critical advantages of vertically aligned nanocomposites (VANs). In SrTiO3 (STO), the ground state is ferroelastic, and the ferroelectricity in STO is suppressed by the orthorhombic transition. Here, we explore whether vertical lattice strain in three-dimensional VANs can be used to induce new ferroelectric phases in SrTiO3:MgO (STO:MgO) VAN thin films. The STO:MgO system incorporates ordered, vertically aligned MgO nanopillars into a STO film matrix. Strong lattice coupling between STO and MgO imposes a large lattice strain in the STO film. We have investigated ferroelectricity in the …

High Ethanol Concentration (77 G/L) Of Industrial Hemp Biomass Achieved Through Optimizing The Relationship Between Ethanol Yield/Concentration And Solid Loading, Jikai Zhao, Youjie Xu, Weiqun Wang, Jason Griffin, Donghai Wang

School of Earth, Environmental, & Marine Sciences Faculty Publications

In this study, the relationships between ethanol yield/concentration and solid loading (6–21%) were investigated to enhance ethanol titer and avoid a random choice of solid loading for simultaneous saccharification and fermentation (SSF). Alkali-pretreated hemp biomass was used for SSF in four scenarios including Case I: 30 filter paper unit (FPU)-cellulase and 140 fungal xylanase unit (FXU)-hemicellulase/g-solid; Case II: 40 FPU-cellulase and 140 FXU-hemicellulase/g-solid; Case III: 30 FPU-cellulase and 140 FXU-hemicellulase/g-solid with 1% Tween80; and Case IV: 30 FPU-cellulase and 140 FXU-hemicellulase/g-solid with particle size reduction (R2 = 0.76–0.93) and quadratic (R2 = 0.96–0.99) correlation with solid loading (6–21%), …

Flexible Versus Simple Trade-In Strategy For Remanufacturing, Zhaojun Yang, Xu Hu, Jun Sun, Yali Zhang

Information Systems Faculty Publications

Some enterprises recently start to offer the flexible trade-in option to attract customers from competitors, in contrast to the simple one that only allows them to return used products to the same manufacturers for new. Based on analytical and numerical analyses, this study compares the environmental impacts of two trade-in strategies (simple versus flexible) in combination with different carbon tax policies. From the perspective of consumer switching behaviour, a Hotelling model with two market segments is established. Under the flexible trade-in strategy, the carbon emission of enterprises turns out to be significantly higher than that under the simple trade-in strategy. …

Imidacloprid Movement Into Fungal Conidia Is Lethal To Mycophagous Beetles, Robin A. Choudhury, Andrew M. Sutherland, Matt J. Hengel, Michael P. Parrella, W. Douglass Gubler

School of Earth, Environmental, & Marine Sciences Faculty Publications

Applications of systemic pesticides can have unexpected direct and indirect effects on nontarget organisms, producing ecosystem-level impacts. We investigated whether a systemic insecticide (imidacloprid) could be absorbed by a plant pathogenic fungus infecting treated plants and whether the absorbed levels were high enough to have detrimental effects on the survival of a mycophagous beetle. Beetle larvae fed on these fungi were used to assess the survival effects of powdery mildew and imidacloprid in a factorial design. Fungal conidia were collected from treated and untreated plants and were tested for the presence and concentration of imidacloprid. The survival of beetles fed …

Li+ Co-Doping Induced Phase Transition As An Efficient Strategy To Enhance Upconversion Of La2zr2o7:Er,Yb Nanoparticles, Santosh K. Gupta, Maya Abdou, Jose P. Zuniga, Partha Sarathi Ghosh, Yuanbing Mao

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

The structural phase transition of materials is one of the most active research areas of solid state and materials chemistry in which atomic rearrangements tune fundamental pysochemical properties during the transition. In most cases, such transition requires high temperature, high pressure, or chemical doping. However, phase transition of complex metal oxides such as La2Zr2O7 has not been studied to enhance the upconversion (UC) and downconversion luminescence of their rare-earth doped nanoparticles (NPs) to meet the demand of their broad applications in solar cells, bioimaging, water purification, etc. In this work, we have successfully co-doped Li+ into La2Zr2O7:Er,Yb NPs to …

Searching For Low Frequency Fast Radio Bursts With Vlite, Suryarao Bethapudi

Theses and Dissertations

The VLITE (VLA Low Band Ionosphere and Transient Experiment; http://vlite.nrao.edu) program performs commensal observations using 16 antennas of the Very Large Array radio telescope from 320-384 MHz. The VLITE-Fast program searches for short time-scale (<100ms) transients, such as Fast Radio Bursts (FRBs), in real time and triggers recording of baseband voltages for offline imaging. Searches are made possible by a 12 node cluster, each housing GPUs for digital signal processing. A real-time Message Passing Interface (MPI)-based co-adder incoherently sums the data streams from all the antennas to boost the signal-to-noise. To undo the dispersion effects of signal propagation through the ionized interstellar medium, the co-added stream is de-dispersed and matched-filtered to search for transients. This operation is completely performed on GPUs by the software package Heimdall . A selection logic is applied to the candidates and interesting candidates with their corresponding data are processed and packaged in a binary file along with a diagnostic plot. Furthermore, a Machine Learning classification is applied on the reduced data product and, based on its decision, baseband voltages are recorded. Reduced data products collected over 126 days of on-sky operation form the VLITE-Fast Pathfinder Survey (VFPS). This pipeline has triggered on single pulses from 7 known radio pulsars. Lastly, the pipeline capabilities are tested against pure random noise and simulated injected signals.

A Comparative Study Of Principals' Perceptions Of Bilingual Education In School Districts In South Texas, Enrique H. De La Cruz

Theses and Dissertations

At a time when school leaders are held accountable for academic achievement and student growth, this study served to inform school leaders, who implement bilingual education programs, on the influence their perceptions have in their students’ academic success. This study examined and described elementary principals’ perceptions about bilingual education in a district implementing an early-exit bilingual program and in a district implementing a dual language bilingual program and its effectiveness to help ELLs achieve academic success. The study focused in determining if elementary principals’ perceptions were a function of their bilingual proficiency or language discourse, level of academic knowledge of …

Searching For Pulsars Using The Long Wavelength Array Telescope, Keeisi A. Caballero Valdez

Theses and Dissertations

Radio pulsars are fascinating celestial objects known to display both periodic and transient behavior. Pulsars are characterized by narrow electromagnetic radiation beams which restrict the number of pulsars visible from Earth due to the necessary alignment of the radiation beam across an observer’s line of sight. Pulsars are useful tools for a broad range of applications and provide important information about the process of stellar evolution, tests for relativistic theories of gravity and the search for low-frequency gravitational waves. Over 2,500 pulsars have been observed since their initial discovery in 1967 but the search for these objects is continuously warranted. …

Unbinding Of Testosterone From The Androgen Receptor And Two Bf-3 Site Mutants, Muniruzzaman Chowdhury

Theses and Dissertations

The androgen receptor (AR) can be activated by molecules binding in the steroid binding pocket. It can also be regulated allosterically by cofactors binding to the AF-2 surface site as well as by exogenous small molecules binding to the BF-3 surface site. Recent data indicated that mutations in the BF-3 site changed the amount of the endogenous steroid needed to activate the receptor, indicating that mutations of BF-3 can cause an allosteric effect. Molecular dynamics and steered molecular dynamics simulations were used to study the allosteric effect of the mutations on AR structure and the unbinding pathways of testosterone (TES) …

Nonwovens Of Ceramic Decorated Cellulose Based Fine Fibers For Leaded Water Purification, Alejandro J. Castillo

Theses and Dissertations

Fine fibers of cellulose acetate were Forcespun and used to make nonwoven mats of cellulose. Nonwovens were activated using a solution combustion synthesis which deposited iron nitride onto fibers. Cellulose and cellulose composite mats were tested as adsorbents for lead ion in water. Cellulose showed slightly higher adsorption capacities (mg/g) up to 1300 mg/g lead loading. Adsorption data were further analyzed using several isotherms, of which the Dubinin-Raduskevich gave the best fits.

Diffusion Of Falsehoods On Social Media, Kelvin Kizito King

Theses and Dissertations

Misinformation has captured the interest of academia in recent years with several studies looking at the topic broadly. However, these studies mostly focused on rumors which are social in nature and can be either classified as false or real. In this research, we attempt to bridge the gap in the literature by examining the impacts of user characteristics and feature contents on the diffusion of (mis)information using verified true and false information. We apply a topic allocation model augmented by both supervised and unsupervised machine learning algorithms to identify tweets on novel topics. We find that retweet count is higher …

An Experimental Thrust Measurement Study On The Nozzle Asymmetry Of Turbulent Pulsed Jets, Cesar Alberto Leos Jr.

Theses and Dissertations

The resurgence of pulsejet engines has renewed the interest of the flow characteristics responsible for the high levels of thrust augmentation that are necessary for Vertical/Short Take-Off and Landing (V/STOL) aircraft. It is well known that pulsation of the engine plays an important role on the thrust performance, but many of the characteristics that are primarily responsible for these enhancements are not well understood. This study is carried out to elucidate the effect of nozzle exit Mach number and the nozzle exit geometry on the characteristics of a high Reynolds number (~105), turbulent free pulsed jet.

Direct thrust measurements are …

Complete Integrability And Discretization Of Euler Top And Manakov Top, Austin Marstaller

Theses and Dissertations

The Euler top is a completely integrable system with physical system implications and the Manakov top is its four-dimensional extension. We are concerned about their complete integrability and the preservation of this property under a specific discretization known as the Hirota-Kimura Discretization. Surprisingly, it is not guaranteed that under any discretization the conserved quantities are preserved and therefore they must be discovered. In this work we construct the Poisson bracket and Lax pair for each system and provide the Lie algebra background needed to do such such constructions.

The Period Of The Coefficients Of The Gaussian Polynomial[N+33], Arturo J. Martinez

Theses and Dissertations

Definition 1. For any N, the central coefficient(s) of [N+33] is denoted by C0(N) and the coefficient that is x ''away" from the central coefficient(s) of [N+33] is denoted by Cx(N).

In [1] the following result is proved:

Theorem 2. The central coefficient(s) of the Gaussian polynomial [N+33] are described by the generating function

[Special characters omitted]

This generating function has period 4.

The main goal of this thesis is to generalize Theorem 0.2 by way of proving the following conjecture:

Conjecture 3. For any x the …

The Long-Term Persistence And Tissue Tropism Of Brazilian Zika Virus In Monodelphis Domestica, Marisol Morales

Theses and Dissertations

Zika virus (ZIKV) rose as a major public health concern due to the congenital abnormalities of infants born to infected mothers during the 2015 Latin American outbreak. While animal models such as transgenic mice and nonhuman primates are used to study ZIKV pathogenesis, they display various limitations. Additionally, the persistence and tissue distribution of long-term ZIKV infection remains unknown. We describe the laboratory opossum, Monodelphis domestica, as a potential new model for ZIKV pathogenesis research to address these issues. We utilized immunohistochemistry, RT-PCR, and ELISA to show that: infant animals inoculated intracerebrally were susceptible to infection, ZIKV infection persisted …

Effects Of Seasonal Variations And Heat Exposure On Antioxidant Expression And Redox Status In The American Oyster, Crassostrea Virginica: Field And Laboratory Studies, Md Sadequr Rahman

Theses and Dissertations

Increasing atmospheric temperatures influence physiological functions in aquatic organisms. In this study, I observed the effects of seasonal (field study) and laboratory heat exposure (16, 22, 26, and 30°C for 1-week) on prooxidant-antioxidant homeostasis in gills and digestive glands of American oyster. Histological analysis showed an increase in mucus secretion with elevated temperatures in both organs. Immunohistochemical analysis showed a significant increase of heat shock protein-70, dinitrophenyl, and 3-nitrotyrosine protein expressions with higher seasonal and laboratory temperatures indicating heat-induced oxidative and nitrosative stress. This was concomitant with gradual rise in cellular apoptosis. Interestingly, catalase and superoxide dismutase expressions also increased …

Creativity And Engagement In Ideas Crowdsourcing: A Situation Awareness Perspective, James Gitau Wairimu

Theses and Dissertations

This dissertation investigates the influence of performance feedback in user motivation and creativity development in idea crowdsourcing engagement. Creativity occurs when users of idea crowdsourcing communities engage in direct and indirect interactions that expose them to a pool of knowledge that enhances their cognitive development leading to the contribution of novel ideas for innovation in organizations. Additionally, participant motivation to engage in ideas crowdsourcing is increased through rewards and conditions that make the ideation process more inclusive and enjoyable. An idea network design is developed by applying social network analysis principles. The idea network design consists of mechanisms for motivating …

Predicting Patterns Of Heavy Metal Contamination In Rio Grande Valley Agricultural Soils, Joy Z. Youwakim

Theses and Dissertations

The Rio Grande Valley of Texas is the statewide leader in the production of produce and grains and is irrigated by the Rio Grande River, in which heavy metal contaminants have been documented by both the International Boundary Water Commission and the United States Geological Survey. This work attempts to observe and document patterns of heavy metal pooling in order to mitigate the increased risk of contamination due to urbanization. We hypothesize that relationships exist between heavy metal content and proximity to roads, land use, and soil type. This research tests these relationships through soil sampling and atomic absorption spectrometry …

The Application Of Advanced Technologies For Agriculture And Rangeland Management, Matthew D. Kutugata

Theses and Dissertations

This project demonstrates two applications of remote sensing in agricultural and rangeland environments. In the first, an unmanned aerial system (UAS) equipped with a multi-spectral sensor was used to estimate canopy cover across four different cover crop trials at four time periods. In the second, a local database of stationary camera trap images of wildlife was used to train a convolutional neural network to automatically catalogue images by identifying the animal in those images. Both projects aimed to provide an example of how remote sensing platforms and machine learning techniques can facilitate the rapid collection and processing of large-scale field …

Autoethnography: A Self Reflection Of The Benefits In Attending A T-Stem High School, Adriana Garza

Theses and Dissertations

The purpose of this autoethnography is to analyze the benefits I obtained as a bilingual, first-generation, Hispanic student by attending a STEM high school. PSJA Thomas Jefferson T-STEM Early College High School provides an Early College experience as well as a Bilingual STEM environment in a district located at La Frontera. This autoethnography uses two techniques to collect data: artifacts and reflective journals. As the researcher, I self-reflected and analyzed my own success story which will be viewed through a Narrative Inquiry lens to answer two questions 1) to what extent has the STEM model/ curriculum influenced my academic …

Analysis Of The Functional Relationship Of Protein Kinase Families Using Phospho-Proteomics Data, David A. Parra Peña

Theses and Dissertations

As cancer research advances, Mass-spectrometry based proteomics is becoming a widely used technique for proteome characterization. Phosphoproteomics is a specific type of proteomics that characterizes proteins with the reversible post-translational modification of phosphorylation PTM), which has allowed the identifications of thousands of phosphorylation sites. These phosphorylation sites, also known as substrates, are known to interact with a protein type named kinases. Studies have shown that abnormal phosphorylation activity is related to cancer diseases. Moreover, these kinases are divided into families, based on the similarity of their catalytic domain, as this part of their amino acid sequence determines a large part …

Embedding Parallelohedra Into Primitive Cubic Networks And Structural Automata Description, Mikhail M. Bouniaev, Sergey V. Krivovichev

School of Mathematical & Statistical Sciences Faculty Publications

The main goal of the paper is to contribute to the agenda of developing an algorithmic model for crystallization and measuring the complexity of crystals by constructing embeddings of 3D parallelohedra into a primitive cubic network (pcu net). It is proved that any parallelohedron P as well as tiling by P, except the rhombic dodecahedron, can be embedded into the 3D pcu net. It is proved that for the rhombic dodecahedron embedding into the 3D pcu net does not exist; however, embedding into the 4D pcu net exists. The question of how many ways the embedding of a parallelohedron can …

Flexible Dye-Sensitized Solar Cells: A Study Of Photoanode And Counter Electrode Materials, Brishty Deb Choudhury

Theses and Dissertations

Compare to flat devices based on rigid substrates, fiber-shaped dye sensitized solar cells hold advantages of smaller size, light weight, facile fabrication, flexibility, and low cost, thus a promising direction for applications such as wearable electronic devices. Due to their unique photovoltaic properties, nanostructured morphologies of TiO2 on flexible substrate have been studied extensively in the recent years for applications in dye sensitized solar cells (DSSCs). Micro-structured electrode materials with high surface area can facilitate rapid charge transport and thus improve the light-to-current conversion efficiency. In the first part of this work the nano-tree morphology of the TiO2 photoanode material …

Signal Processing Combined With Machine Learning For Biomedical Applications, Md Shakhawat Hossain

Theses and Dissertations

The Master’s thesis is comprised of four projects in the realm of machine learning and signal processing. The abstract of the thesis is divided into four parts and presented as follows,

Abstract 1: A Kullback-Leibler Divergence-Based Predictor for Inter-Subject Associative BCI.

Inherent inter-subject variability in sensorimotor brain dynamics hinders the transferability of brain-computer interface (BCI) model parameters across subjects. An individual training session is essential for effective BCI control to compensate for variability. We report a Kullback-Leibler Divergence (KLD)-based predictor for inter-subject associative BCI. An online dataset comprising left/right hand, both feet, and tongue motor imagery tasks was used to …

Influence Of Landscape Factors On Wildlife Presence And Road Mitigation Structure Performance, Taylor M. Hopkins

Theses and Dissertations

There are roughly 80 ocelots (Leopardus pardalis) remaining in the United States, with the entire population constrained to south Texas, with roadkill being a predominant source of mortality. To prevent additional roadkill and maintain wildlife movement, Texas Department of Transportation constructed 11.9 kilometers of wildlife exclusion fencing, 5 wildlife crossing structures (WCS), and 18 wildlife guards on State Highway 100. This thesis focused on determining the effort required for a control-impact monitoring study, the influence of biotic and abiotic factors around the roadway on wildlife presence, and the performance of mitigation structures and the road mitigation corridor. This …

Improving Hardware Implementation Of Cryptographic Aes Algorithm And The Block Cipher Modes Of Operation, Chu-Wen Cheng

Theses and Dissertations

With ever increasing Internet traffic, more business and financial transactions are being conducted online. This is even more so during these days of COVID-19 pandemic when traditional businesses such as traditional face to face educational systems have gone online requiring huge amount of data being exchanged over Internet. Increase in the volume of data sent over the Internet has also increased the security vulnerabilities such as challenging the confidentiality of data being sent over the Internet. Due to sheer volume, all data will need to be effectively encrypted. Due to increase in the volume of data, it is also important …

Computational Complexity Characterization Of Protecting Elections From Bribery, Lin Chen, Ahmed Sunny, Lei Xu, Shouhuai Xu, Zhimin Gao, Yang Lu, Weidong Shi, Nolan Shah

Computer Science Faculty Publications

The bribery problem in election has received considerable attention in the literature, upon which various algorithmic and complexity results have been obtained. It is thus natural to ask whether we can protect an election from potential bribery. We assume that the protector can protect a voter with some cost (e.g., by isolating the voter from potential bribers). A protected voter cannot be bribed. Under this setting, we consider the following bi-level decision problem: Is it possible for the protector to protect a proper subset of voters such that no briber with a fixed budget on bribery can alter the election …